CLJS-1097: source map url for AOTed cljs.core is wrong

Allow supplying custom :source-map-url to cljs.compiler/compile-file*

Rewrite source map JSON "file" for core to be the correct value according to
build options

Author: swannodette

src/clj/cljs/closure.clj

@@ -1580,6 +1580,7 @@ should contain the source for the given namespace name."
     (env/with-compiler-env (env/default-compiler-env)
       (comp/compile-file src dest
         {:source-map true
+         :source-map-url "core.js.map"
          :output-dir (str "src" File/separator "cljs")})
       (ana/write-analysis-cache 'cljs.core cache))))
 

src/clj/cljs/compiler.clj

@@ -15,7 +15,8 @@
             [cljs.env :as env]
             [cljs.tagged-literals :as tags]
             [cljs.analyzer :as ana]
-            [cljs.source-map :as sm])
+            [cljs.source-map :as sm]
+            [clojure.data.json :as json])
   (:import java.lang.StringBuilder
            java.io.File))
 
@@ -989,7 +990,11 @@
               (spit dest (slurp cached))
               (when (true? (:source-map opts))
                 (spit (io/file (str dest ".map"))
-                  (slurp (io/resource "cljs/core.aot.js.map"))))
+                  (json/write-str
+                    (assoc
+                      (json/read-str (slurp (io/resource "cljs/core.aot.js.map")))
+                      "file"
+                      (str (io/file (util/output-directory opts) "cljs" "core.js"))))))
               (ana/parse-ns src dest nil))
             (with-open [out ^java.io.Writer (io/make-writer dest {})]
               (binding [*out* out
@@ -1028,7 +1033,8 @@
                                   {:source-map (:source-map sm-data)}))]
                       (when (and sm-data (= (:optimizations opts) :none))
                         (let [sm-file (io/file (str (.getPath ^File dest) ".map"))]
-                          (emits "\n//# sourceMappingURL=" (.getName sm-file)
+                          (emits "\n//# sourceMappingURL="
+                            (or (:source-map-url opts) (.getName sm-file))
                             (if (true? (:source-map-timestamp opts))
                               (str "?rel=" (System/currentTimeMillis))
                               ""))